Current issues in economics

Teaching ethics: the sub-prime crisis

Teaching ethics to my Yr 10 class I have used the sub-prime crisis as an example. As with behavioural economics the conventional view of finance assumes that markets are efficient and that the price of shares, bonds and other financial instruments are a reflection of the fundamental economic values that they represent. Behavioural finance is all about understanding why and how financial markets are inefficient. If there is a difference between the market price of a share or bond and its fundamental value then in conventional economics no one can make money in financial markets by exploiting the difference.

Global Financial Crisis

In July 2007 a loss of confidence by US investors in the value of sub-prime mortgages caused a liquidity crisis. Sub-prime mortgages were loans that were high risk and many mortgage holders unable to meet their repayments. The mortgages were pooled into what was know as a Collaterised Debt Obligation (CDO) which were sliced into tranches – safe – okay – risky. Investors tended to buy safe tranches as they were rated AAA by the rating agencies. However the rating agencies were very generous in their assessment of these investments as they were paid by the banks who created the CDOs. Banks also were able to take out insurance on the CDO even if they didn’t own them. This was called a Credit Default Swap (CDS).

The flow chart (above) and video (below) shows how Goldman Sachs sold a CDO called Timberwolf to investors and proceeded to bet against that investment by buying insurance from AIG so that when the CDO failed they got a pay out from them. As you maybe aware AIG sold a lot of CDS’s and ultimately had to be bailed out by the US government. However a significant portion of the bailout money went to the banks that had created the problem.

Below is another very good clip from the Big Short that explains how the mortgage market brought down the financial system. Good references to CDO’s in which celebrity chef Anthony Bourdain compares fish to finance?